In various communication systems a user device communicates with a server over a communication network using suitable communication protocols. One protocol that is suitable for request-response communication is the Hypertext Transfer Protocol (HTTP). HTTP is specified, for example, by the Network Working Group of the Internet Engineering Task Force (IETF®), in “Hypertext Transfer Protocol—HTTP/1.1,” Request for Comments (RFC) 2616, June, 1999, which is incorporated herein by reference.